At the Ironman 70.3 World Championships in Nice, France on 12 & 13 September 2026, we noticed many athletes (Pro and Age-Group) removing their EZ Hydrogains from their rear saddle in an attempt to save weight for the very hilly course!

We were wondering was this the correct decision?

An analysis was conducted, where we modelled an average female and male age-grouper and top-end female and male pro triathletes and simulated their times without the EZ Hydrogains and then with it. From several wind tunnel test sessions we have always found that the EZ Hydrogains saves at least 5 Watts and have seen many people saving up to and over 15 Watts, therefore to make it fair we showed three variations with different levels of Watt savings.

For the specifics, the model was simulated with different powers and CdA's for flat, uphill and downhill segments to accurately capture the nature of a hilly course. For Age-Group athletes, the simulation assumes the aerodynamics uphill don't change which is a pessimistic approach and actually means that these predictions are likely a low estimate!

The difference in weight between no EZ Hydrogains and with EZ Hydrogains was taken as 1kg (~250g for BTS System, ~750g for fluid with a 750ml bottle). This should also be considered as quit e a high weight difference as someone could easily just have taken empty or low-filled bottles on their bike for a total weight significantly under 1kg.

The results shown in the table above for Age-Group athletes clearly show that in no case, using the EZ Hydrogains would have lost you time. Athletes could have taken up some fluid or even empty bottles to further increase their aerodynamic advantage and reduce weight which would have created even larger time gaps.

When looking at many of the Age-Group podiums, most have time gaps which are less than the potential time savings we have displayed, indicating that removing the EZ Hydrogains was a mistake.

For the Professional athletes, a more in depth analysis was conducted, where it was assumed that these athletes would be staying in the TT position for longer on the shallower gradient sections of the climb, therefore an aerodynamic advantage becomes more critical. Taking this into consideration the Watt savings are shown above where we can see time savings that would have been critical at the pointy end of each field.